By temporarily blocking muscle movement, injectable commercial neurotoxins have become a mainstay of the treatment of dynamic wrinkles; however, because results can be subtle or extreme, their use has been both celebrated and maligned. A clear understanding of the anatomy and directionality of the involved muscles is necessary to create a natural appearance, rather than one that is expressionless. Selective injection of specific muscle groups allows the clinician to control treatment results. As more botulinum toxin products become commercially available, it is clear that differences exist and the nuances of dosing and injection pattern continue to be elucidated. Part 1 of this series discussed the science of the currently available botulinum toxin products. Here we outline best practices for their use in aesthetic dermatology.